A. Test Procedures. LG LRMM1430SW, LRMM1430SB

11. TEST AND CHECKOUT PROCEDURES, AND TROUBLESHOOTING

CAUTIONS

1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE

FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR

AND REMOVING THE LEAD WIRES FROM THE INVERTER MODULE.

2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER OF

WATER IN CONTAINER) IN THE OVEN.

A. TEST PROCEDURES

COMPONENTS

INVERTER

(Lead wires removed)

TEST PROCEDURE RESULTS

CN702

Heat Sink

E701

120V AC

MAGNETRON

(Lead wires removed)

CN701

High Voltage

Output to

Magnetron

CN703

Control Signal

In/Out

Note: Do not try to repair the inverter board, nor try to make any adjustments to the board.

Check wiring to the inverter:

1. Unplug the oven’s main power supply.

2. Visually inspect 4 connectors on the inverter board: CN701, CN702, CN703, E701 to see whether there are any signs of failure due to loose wires, bad crimping, sign of overheating, etc.

1. Measure the resistance.

(Ohm-meter scale: Rx1)

• Filament terminal

2. Measure the resistance.

(Ohm-meter scale: Rx1000)

• Filament to chassis

Normal: Less than 1 ohm

Normal: Infinite

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COMPONENTS

SENSOR

TEST PROCEDURE

Antenna

Gasket

Chassis

RESULTS

Filament

NOTE: When testing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition.

1. Disconnect sensor connector from micom computer board.

2. Measure resistance terminal to terminal

(Select the ohm scale on the meter)

Normal: Approximately

BK-RD: 5.2 Kohms

RD-WH: 2.1 Kohms

BK-WH: 2.1 Kohms

Abnormal:

Infinite or several

*Sensor cooking condition

1. Oven should be plugged in at least 5 minutes before sensor cooking.

2. Room temperature should not exceed 95˚F.

3. Be sure the exterior of the cooking container and the interior of the oven are dry.

4. The oven will not generate microwave energy for the first

28 seconds of the sensor cooking cycle.

NOTE: MAKE SURE THE LEAD WIRES ARE

IN THE CORRECT POSITION.

WHEN REMOVING THE LEAD

WIRES FROM THE PARTS, BE

SURE TO GRASP THE

CONNECTOR, NOT THE WIRES.

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COMPONENTS

RELAY

TEST PROCEDURE

Check for continuity of relay with an ohm-meter.

(Remove lead wires from relay and operate the unit.)

RESULTS

Normal: Approx.

ON: 0 ohm

OFF:

∞ ohms

Abnormal: Infinite or several ohms.

Relay 2

FAN MOTOR

(Wire leads removed)

Measure the resistance.

(Ohm-meter scale: R x 100)

A(RD)

B(BK)

C(WH)

Normal: Approx. 50 ~ 150 ohms

Abnormal: Infinite or several ohms.

TURNTABLE

MOTOR

(Wire leads removed)

Measure the resistance.

(Ohm-meter scale: R x 1000)

Normal: Approx. 2 ~ 4K ohms

Abnormal: Infinite or several ohms.

NOTE : • A MICROWAVE LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR

ANY REASON.

• MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.

• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT

THE WIRES.

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